Nix tweeted on Sunday night: "The road to recovery begins tomorrow."
A source told ESPN that Nix is expected to miss the rest of the regular season.
No. 17 Auburn (6-4) plays at South Carolina on Saturday and wraps up the regular season the following weekend at home against No. 2 Alabama.
Nix, a junior, has completed 197 of 323 passes for 2,294 yards, 11 touchdowns and three interceptions this season. He also has rushed for three touchdowns.
With Nix sidelined, Auburn is likely to turn to TJ Finley at quarterback.
Finley, who transferred from LSU this past offseason, led the offense on the final series against Mississippi State. He has completed 17 of 33 passes for 275 yards and two touchdowns this season.